The present invention relates to a disk drive for loading a disk cartridge accommodating a recording medium such as an optical disk and a magneto-optical disk to record or reproduce data such as video data and audio data onto or from the recording medium.
A disk cartridge 1 as shown in FIGS. 1, 42, and 43 has conventionally been developed. The disk cartridge 1 is a substantially rectangular flat case in which a double-sided disk 2 is rotatably accommodated. The double-sided disk 2 is a recording medium such as an optical disk and a magneto-optical disk having opposite recording surfaces which data can be recorded on and reproduced from. The disk cartridge 1 has a front end surface 1a as an insertion end surface from which the disk cartridge 1 is inserted into a disk drive 11 to be hereinafter described. The disk cartridge 1 has upper and lower surfaces 1b symmetrical with each other. The upper and lower surfaces 1b are formed with a pair of upper and lower recesses 3 in a longitudinal region offset to the front end surface 1a over the substantially entire width. The upper and lower recesses 3 are formed with a pair of upper and lower elongated windows 4 each extending from a central position corresponding to a center hole 2a of the double-sided disk 2 to a front position near the center of the front end surface 1a. A dustproof shutter 5 formed from a plastic or metallic thin plate into a U-shaped structure as viewed in side elevation is mounted on the disk cartridge 1 so as to be inserted from the front end surface 1a in the upper and lower recesses 3. The shutter 5 is slidable along the front end surface 1a from its central position in one direction or opposite directions, thereby simultaneously opening the upper and lower windows 4. The shutter 5 is normally biased by a return spring (not shown) incorporated inside of the front end surface 1a of the disk cartridge 1 from a shutter open position shown in FIG. 43 to a shutter closed position shown in FIG. 42. The shutter 5 has a front end surface 5a projecting frontward by an amount slightly greater than the amount of projection of right and left corner portions 1c of the front end surface 1a of the disk cartridge 1. The central portion of the front end surface 1a of the disk cartridge 1 inclusive of the front end surface 5a of the shutter 5 is a portion weakest in strength. Each of the upper and lower surfaces 1b of the disk cartridge 1 is formed with a pair of right and left positioning holes 6 at a longitudinal position offset to a rear end surface 1d of the disk cartridge 1. Further, the disk cartridge 1 has right and left side surfaces 1e each formed with a notch 7 for a cartridge loading mechanism and a notch 8 for a disk changer respectively near the front and rear ends of each side surfaces 1e. 
As shown in FIGS. 44 to 46B, the disk drive 11 for recording and reproducing data such as video data and audio data onto and from the double-sided disk 2 of the disk cartridge 1 has a front panel 12 formed with a laterally elongated cartridge insertion opening 13. The cartridge insertion opening 13 is normally closed by a dustproof front door 14. The front door 14 has a pair of right and left arms pivotably supported at their upper ends through horizontal shafts 15 to the inside of the front panel 12, so that the front door 14 is rotatable about the horizontal shafts 15 in the opposite directions of arrows c and d. The front door 14 is of an inward opening type such that it is opened inward of the front panel 12 in the direction of the arrow c about the horizontal shafts 15 against a biasing force of return springs (not shown). As shown in FIG. 45A, the disk cartridge 1 is inserted from its front end surface 1a into the cartridge insertion opening 13 in the direction of an arrow a. As shown in FIGS. 45B and 45C, the disk. cartridge 1 is further inserted horizontally through the cartridge insertion opening 13 into the disk drive 11 in such a manner that the front end surface 1a of the disk cartridge 1 pushes to open the front door 14 in the direction of the arrow c against the return springs. Thereafter, the disk cartridge 1 is drawn into the disk drive 11 by a cartridge loading mechanism (not shown) provided in the disk drive 11. During this operation, the shutter 5 of the disk cartridge 1 is slid laterally to the shutter open position to open the upper and lower windows 4. Subsequently, the disk cartridge 1 is loaded to a loading end position and the double-sided disk 2 is then rotated at a high speed by a spindle motor (not shown) provided in the disk drive 11. Further, a pair of upper and lower optical pickups (both not shown) each functioning as a data record/playback head are vertically inserted into the upper and lower windows 4, respectively, to record or reproduce data such as video data and audio data onto or from the opposite surfaces of the double-sided disk 2 simultaneously or selectively. After recording or reproducing the data, the disk cartridge 1 is ejected to be pulled out of the cartridge insertion opening 13 of the disk drive 11 in the direction of an arrow b as shown in FIG. 45A. As a result, the front door 14 is rotated in the direction of the arrow d by the return springs to close the cartridge insertion opening 13.
The conventional disk drive 11 has a door opening/closing mechanism intended to close the cartridge insertion opening 13 with the front door 14 also during recording or reproducing data onto or from the double-sided disk 2 of the disk cartridge 1 drawn into the disk drive 11, thereby preventing foreign matter, dust, etc. from entering the disk drive 11 from the cartridge insertion opening 13 during recording or reproducing data to ensure high dustproof performance. This kind of door opening/closing mechanism is so configured as to mechanically link the cartridge loading mechanism and the front door 14 by using a link, cam, etc. In ejecting the disk cartridge 1, the cartridge loading mechanism is driven to raise the disk cartridge 1 from the loading end position to the loading start position. In concert with the rising motion of the disk cartridge 1, the door opening/closing mechanism operates to open the front door 14 and allow the disk cartridge 1 to be pulled out of the cartridge insertion opening 13. After the disk cartridge 1 is ejected, the door opening/closing mechanism operates to close the front door 14 to thereby close the cartridge insertion opening 13. Further, in loading the disk cartridge 1, the cartridge loading mechanism is driven to lower the disk cartridge 1 from the loading start position to the loading end position. After the disk cartridge 1 reaches the loading end position, the door opening/closing mechanism operates to close the front door 14.
However, such a structure that the front door is opened and closed by the cartridge loading mechanism mechanically linked to the front door through a link, cam, etc. is remarkably complicated in mechanism to increase the number of parts and the number of man-hours for assembly, causing an increase in cost. Furthermore, since the front door is always linked to be opened and closed by the cartridge loading mechanism, the cartridge insertion opening is needlessly opened by operating the cartridge loading mechanism irrespective of whether the disk cartridge is present or absent in the disk drive, causing a reduction in dustproof effect. Furthermore, it is necessary to additionally provide an improper insertion prevention mechanism for preventing improper insertion (double insertion) such that although a disk cartridge has already been loaded to the loading end position by the cartridge loading mechanism, another disk cartridge may be inserted into the disk drive by mistake, thus making the structure more complicated.
It is accordingly an object of the present invention to provide a disk drive in which the cartridge insertion opening can be closed by the front door in concert with the loading operation of the disk cartridge without mechanically linking the front door to the cartridge loading mechanism.
According to the present invention, a disk cartridge is inserted into a cartridge insertion opening to inward open a front door. When the disk cartridge is inserted into a loading start position in the disk drive, the disk cartridge is lowered from the loading start position to a loading end position by a cartridge loading mechanism. At this time, the disk cartridge is separated from the front door, and the front door is biased to a door closed position by biasing means to thereby close the cartridge insertion opening.
As described above, when the disk cartridge inserted to the loading start position in the disk drive is lowered from the loading start position to the loading end position by the cartridge loading mechanism, the disk cartridge is separated from the front door, so that the front door is closed by the biasing means for normally biasing the front door toward the door closed position. Thus, it is not necessary to provide a mechanism for mechanically linking the front door to the cartridge loading mechanism.
Other objects and features of the invention will be more fully understood from the following detailed description and appended claims when taken with the accompanying drawings.